This invention relates to electrophotographic color printer arrangements.
Conventional electrophotographic color printer arrangements are in many cases inconveniently large in size and, in an effort to reduce size, some printers locate heat generating components close enough to the photoreceptor to subject the photoreceptor to undue heating, causing premature aging and substantial wear of the surface.
In the Chamitski et al. U.S. Pat. No. 5,291,245, an electrophotographic apparatus includes a photoreceptor belt supported for motion in a triangular path with four sets of charging, exposure, and development stations horizontally spaced adjacent to one portion of the belt, thereby requiring the printer to have a substantial length in the horizontal direction.
The Smith U.S. Pat. No. 5,313,259 discloses a multicolor electrophotographic printer having a photoreceptor belt which follows a generally oval path which is elongated in a vertical direction with three vertically aligned printing stations adjacent to the photoreceptor on one side of the oval path and one further printing station adjacent to the photoreceptor on the opposite side of the path. After an image has been generated and transferred from the photoreceptor belt to a sheet of paper, the paper is transported by a belt to a remote heat generating fuser which is spaced horizontally from the vertically elongated belt path to minimize heating of the photoreceptor from the fuser.
The patent to Maruyama et al. U.S. Pat. No. 5,473,421 discloses an electrophotographic multicolor image printer having a photoreceptor belt which is driven in a generally triangular path oriented with a long dimension in the vertical direction and includes a conveyor to convey a sheet of paper to which an image has been transferred to a remote fuser which is spaced in the horizontal direction from the photoreceptor belt.
In the Loewen et al. U.S. Pat. No. 5,557,377 a multicolor electrophotographic printer has a photoreceptor belt extending in a generally oval path which is elongated in the horizontal direction. In this printer, liquid toners are used which are pumped from liquid toner supply containers beneath the belt to developing units adjacent to the lower side of the belt.
The Haneda et al. U.S. Pat. No. 5,257,037 discloses an electrophotographic color printer having a photoreceptor belt supported in a generally elongated path oriented at an angle of 5.degree. to 30.degree. to the horizontal. A stepped arrangement of exposure lasers and developing units are mounted adjacent to the lower side of the photoreceptor path and paper sheets are transported from a sheet feed device disposed beneath the exposure and developing units to a transfer station at the lower end of the belt and then to a fuser adjacent to the lower end of the photoreceptor belt after transfer of an image. In this printer, a used toner recovery chamber is located inside the photoreceptor belt loop and toner cleaned from the surface of the photoreceptor after transfer of the image is directed by a screw conveyer into the used toner recovery chamber.
The Ikeda et al. U.S. Pat. No. 5,541,722 and the Haneda et al. U.S. Pat. No. 5,557,394 disclose electrophotographic color printing arrangements in which exposure units are mounted inside a moving photoreceptor having a transparent support surface. Since exposure units can be provided which do not occupy a significant amount of space, however, such arrangements do not per se reduce significantly the size of a multicolor electrophotographic printer.